Dopaminergic modulation of human bronchial tone

Ga. Cabezas et al., Dopaminergic modulation of human bronchial tone, ARCH MED R, 32(2), 2001, pp. 143-147
Citations number
Categorie Soggetti
Medical Research General Topics
Journal title
ISSN journal
0188-4409 → ACNP
Year of publication
143 - 147
SICI code
Background. Dopamine exerts inhibitory and excitatory effects on different systems. Its effect on human bronchial tone is controversial, It has been r eported that dopamine has no acute effect on human airways from normal subj ects or those with asthma background. However, inhaled or infused dopamine decreased histamine-induced bronchoconstriction in both normal and asthmati c subjects. We examined the possible modulating effect of dopamine on bronc hial diameter by administering inhaled dopamine and the DA(2) dopaminergic blocker metoclopramide (MTC) to subjects with various degrees of bronchial tone. Methods. We examined 50 volunteers. Arterial blood pressure and heart rate were deter mined in each subject. By means of spirometry, we measured force d vital capacity (FVC), forced expiratory volume in the first second (FEV,) , maximal forced expiratory flow (FEFmax), and forced expiratory flow at 50 % of vital capacity (FEF50), before and after each treatment. By inhalation with a nebulizer, we administered the following: a) dopamine (0.5 mug/kg/m in) to 10 healthy subjects, 10 subjects with asthma without acute bronchosp asm (AWAB), and nine subjects with acute asthma attack (AAA), and b) intrav enous (i.v.) metoclopramide (7 mug/kg/min) was administered to 10 healthy s ubjects and 11 subjects with AWAB. For ethical reasons, MTC was not used in subjects with acute asthma attack. Non-parametric Wilcoxon test for paired samples, ANOVA test, and Bonferroni multiple comparison test were performe d. Results. Inhaled dopamine increased FEV1 and FVC, FEFmax and FEF50 in the A AA group, but there were no modifications in the healthy group or in the AW AB group. Metoclopramide did not induce changes in respiratory parameters i n healthy individuals or in those with AWAB. Conclusions. Inhaled dopamine is able to induce bronchodilatation when the bronchial tone is already increased by acute asthma attack but did not modi fy the resting bronchial tone in normal subjects or in asthmatics without: acute bronchospasm. Additionally, DA, blockade with metoclopramide did not modify resting bronchial tone. Dopamine exerts a modulatory effect on the b ronchial tone of human airways depending on the degree of preexisting tone. (C) 2001 IMSS. Published by Elsevier Science Inc.